Energy savings analysis in cold storages with thermal energy storage using various control strategies
Student name: Mr Sarath Kanth Chaganti
Guide: Dr Som Mondal
Year of completion: 2018
Host Organisation: TERI School of Advanced Studies
Supervisor (Host Organisation): Dr Som Mondal
Abstract: India witnessed phenomenal growth in production of varieties of commodities over the last decade. Even with large production quantities, India’s contribution in global farm trade is very minimal. New technological interventions are needed to bring down operating costs, and to improve quality of end produce. Cooling loads constitute more than seventy percent of the total energy consumption in cold storages. The primary motivation of incorporating thermal energy storage comes from the fact that it is an energy saving solution and has a huge potential to save operating costs in cold storages, along with automation of operations and monitoring, ensuring controlled atmosphere in a cold storage. By installing storage, harnessing the cheaper and burden less electricity rates offered by the utilities during off-peak hours is possible. This is what is exactly analyzed in this work; the energy savings and operating costs savings when a thermal energy storage system (TES) is employed in a cold storage with proper control mechanisms and making use of the on-peak and off-peak price disparity. Three conventional control strategies namely, chiller prioritized control, constant proportion control, storage prioritized control and lastly optimal control have been analyzed for a particular design day taking the basic plant model into consideration. We compared all the strategies and their results which were obtained using excel worksheet. We found that for that particular design day, one control, chiller priority has under-performed and showed extra energy consumption while the rest of the controls actually showed energy savings of nearly 8%, 17% and 25% respectively making better use of the storage. The optimal control which focuses on optimizing the cost function is accepted worldwide as the best control for a cooling plant with storage, and it has been validated through our results as well. The future work mentioned in the report will certainly give us more refined results.
KEYWORDS:
Cold storage
Thermal Energy Storage
Cooling loads
Control strategies
Optimal control
